Planarization methods for patterned media disks

Abstract

A method is provided for forming a plurality of regions of magnetic material in a substrate having a first approximately planar surface. The method comprises the steps of fabricating projections in the first surface of the substrate, depositing onto the first surface a magnetic material in such a way that the tops of the projections are covered with magnetic material, and depositing filler material atop the substrate so produced. The filler material may then be planarized, for example by chemical-mechanical polishing. In an alternative embodiment magnetic material is deposited on a substrate and portions of it are removed, leaving islands of material. Filler material is then deposited, which may be planarized.

1. A method of forming a plurality of regions of magnetic material in a substrate having a first approximately planar surface, comprising:
 fabricating a plurality of projections in the first surface of the substrate such that each projection comprises a top; 
 depositing, onto the first surface of the substrate after fabrication of the projections, a magnetic material in such a way that the tops of the projections are covered with the magnetic material and the magnetic material on the top of each projection is magnetically decoupled from the magnetic material on the tops of the other projections; 
 depositing stop material atop the substrate produced in step b), the stop material comprising a material chosen from the group consisting of diamond-like carbon, TaN, TiN, and tantalum; and 
 depositing filler material above the stop material deposited atop the substrate. 
 
     
     
       2. The method of  claim 1 , wherein the fabricating comprises: depositing a the mask material atop the first surface of the substrate, depositing resist atop the mask material, patterning the resist, transferring the pattern in the resist to the mask material, and removing the mask material. 
     
     
       3. The method of  claim 2 , wherein the mask material is chosen from the group consisting of silicon nitride and silicon dioxide. 
     
     
       4. The method of  claim 1 , further comprising depositing a layer of further material atop the filler material. 
     
     
       5. The method of  claim 1 , wherein the magnetic material comprises multiple layers. 
     
     
       6. The method of  claim 5 , wherein the magnetic material comprises Ta, (CoIPd), and Pd layers. 
     
     
       7. The method of  claim 1 , further comprising planarizing the filler material. 
     
     
       8. The method of  claim 7 , wherein the planarizing of the filler material comprises chemical-mechanical polishing (CMP). 
     
     
       9. The method of  claim 2 , wherein the mask material is removed using reactive ion etching. 
     
     
       10. The method of  claim 7 , further comprising depositing a mask atop the magnetic material such that the mask serves as a stop material for the planarizing. 
     
     
       11. The method of  claim 1 , wherein the filler material is deposited to a thickness approximately equal to the tops of the projections covered with the magnetic material. 
     
     
       12. The method of  claim 1 , wherein the projections are spaced at a density of at least about 300 billion per square inch. 
     
     
       13. A method of forming a plurality of regions of magnetic material in a substrate having a first approximately planar surface, comprising:
 fabricating projections in the first surface of the substrate such that each projection comprises a top; 
 depositing, over the first surface of the substrate after fabrication of the projections, a magnetic material in such a way that the tops of the projections are covered with the magnetic material and the magnetic material on the top of each projection is magnetically decoupled from the magnetic material on the tops of the other projections; 
 depositing a mask atop the magnetic material; 
 depositing filler material above the substrate; 
 depositing a further layer of material atop the filler material, the further layer of material being deposited to approximately the same thickness as the mask; and 
 planarizing the filler material by applying spin-coated or dip-coated polymer and planarization of the applied polymer by disk burnishing. 
 
     
     
       14. The method of  claim 7 , wherein the planarizing of the filler material comprises planarization with a directional high-incidence-angle broad ion beam. 
     
     
       15. The method of  claim 7 , wherein the planarizing of the filler material comprises application of spin-coated or dip-coated polymer and planarization of the applied polymer by disk burnishing. 
     
     
       16. The method of  claim 13 , wherein the projections are spaced at a density of at least about 300 billion per square inch. 
     
     
       17. The method of  claim 9 , further comprising patterning the mask material using a resist material deposited atop the mask material. 
     
     
       18. A method of forming a plurality of regions of magnetic material in a substrate having a first approximately planar surface, comprising:
 fabricating a plurality of projections in the first surface of the substrate such that each projection comprises a top, the fabricating comprising:
 depositing a mask material atop the first surface of the substrate, 
 depositing resist atop the mask material, 
 patterning the resist, 
 transferring the pattern in the resist to the mask material, and a 
 removing the mask material; 
 
 depositing, onto the first surface of the substrate after fabrication of the projections, a magnetic material in such a way that the tops of the projections are covered with the magnetic material and the magnetic material on the top of each projection is magnetically decoupled from the magnetic material on the tops of the other projections; 
 depositing filler material above the substrate; and 
 removing the resist via lift-off. 
 
     
     
       19. A method of forming a plurality of regions of magnetic material in a substrate having a first approximately planar surface, comprising:
 fabricating projections in the first surface of the substrate such that each projection comprises a top; 
 depositing, over the first surface of the substrate after fabrication of the projections, a magnetic material in such a way that the tops of the projections are covered with the magnetic material and the magnetic material on the top of each projection is magnetically decoupled from the magnetic material on the tops of the other projections; 
 depositing a mask atop the magnetic material, the mask having a thickness, the mask comprising a first material; 
 depositing filler material above the substrate; 
 depositing a further layer of material atop the filler material, the further layer of material comprising the first material; and 
 planarizing the filler material by applying spin-coated or dip-coated polymer and planarization of the applied polymer by disk burnishing.